Solar Discovery

Charging batteries properly requires administering the right amount of current at the right voltage. Most charging equipment automatically regulates these values. Some chargers allow the user to set these values. Both automatic and manual equipment can present difficulties in charging. Tables 2 & 3 list most of the necessary voltage settings one might need to program a charger. In either case the original instructions for your charging equipment should also be referenced for proper charging.

Here is list of helpful items to remember when charging.

1. Become familiar with and follow the instructions issued by the charger manufacturer.
2. Batteries should be charged after each period of use.
3. Lead acid batteries do not develop a memory and need not be fully discharged before recharging.
4. Charge only in well-ventilated area. Keep sparks or flames away from a charging battery.
5. Verify charger voltage settings are correct (Table 2).
6. Correct the charging voltage to compensate for temperatures above and below 80o F. (Add .028 volt per cell for every 10o below 80o F and subtract .028 volt per cell for every 10o above 80o F)

Table 2. Charger Voltage Settings for Flooded Batteries

System Voltage
Charger Voltage Setting
6V
12V
24V
36V
48V
Daily Charge
7.4
14.8
29.6
44.4
59.2
Float
6.6
13.2
26.4
39.6
52.8
Equalize
7.8
15.5
31.0
46.5
62.0

Table 3. Charger Voltage Settings for VRLA Batteries
Charger Voltage Setting
System Voltage
12V
24V
36V
48V
Daily Charge
13.8 - 14.1
27.6 - 28.2
41.4 - 42.3
55.2 - 56.4
Float
13.5
26.4
39.6
52.8

1. Check water level (see the Watering section).
2. Tighten all vent caps before charging.
3. Prevent overcharging the batteries. Overcharging causes excessive gassing (water breakdown), heat buildup, and battery aging.
4. Prevent undercharging the batteries. Undercharging causes stratification.
5. Do not charge a frozen battery.
6. Avoid charging at temperatures above 120o F.
   

Additional VRLA Charging Instructions:

1. Become familiar with and follow the instructions issued by the charger manufacturer.
2. Verify charger has necessary VRLA setting.
3. Set charger to VRLA voltage settings (Table 3).
4. Do not overcharge VRLA batteries. Overcharging will dry out the electrolyte and damage battery.

Periods of inactivity can be extremely harmful to lead acid batteries. When placing a battery into storage, follow the recommendations below to insure that the battery remains healthy and ready for use.

NOTE: Storing, charging or operating batteries on concrete is perfectly OK.

The most important things to avoid:

1. Freezing. Avoid locations where freezing temperature is expected. Keeping a battery at a high state of charge will also prevent freezing. Freezing results in irreparable damage to a battery's plates and container.
2. Heat. Avoid direct exposure to heat sources, such as radiators or space heaters. Temperatures above 80° F accelerate the battery's self-discharge characteristics.
   

Step by step storage procedure:

1. Completely charge the battery before storing.
2. Store the battery in a cool, dry location, protected from the elements.
3. During storage, monitor the specific gravity (flooded) or voltage. Batteries in storage should be given a boost charge when they show a 70% charge or less. See Table 1 in the Testing Section.
4. Completely charge the battery before re-activating.
5. For optimum performance, equalize the batteries (flooded) before putting them back into service. Refer to the Equalizing section for this procedure.

Batteries seem to attract dust, dirt, and grime. Keeping them clean will help one spot trouble signs if they appear and avoid problems associated with grime.

1. Check that all vent caps are tightly in place.
2. Clean the battery top with a cloth or brush and a solution of baking soda and water.
   When cleaning, do not allow any cleaning solution, or other foreign matter to get inside the battery.
3. Rinse with water and dry with a clean cloth.
4. Clean battery terminals and the inside of cable clamps using a post and clamp cleaner.
   Clean terminals will have a bright metallic shine.
5. Reconnect the clamps to the terminals and thinly coat them with petroleum jelly (Vaseline) to prevent corrosion.
6. Keep the area around batteries clean and dry.